Hammer mill



Aug. 27, 1935. E. L. BARTELS HAMMER MILL Filed Sept. 12, 1932 ATTORNEYS,

.Patentc d Aug. 2'], 1935 PATENT OFFICE HAMMER MILL Elmer L. Bartels, Independen, Mo., assignor to Gustave C. Blumstenxel, Kansas City, Mo.

Application September 12, 1932, Serial No. 632,648

8 Claims. (Cl. 83-11) This invention relates to improvements in machines for grinding or reducing material, and par: ticularly to a hammer mil] in which a rotor is arranged for rapid rotation within a casing t engage and pulverize the material therein.

The principal object of this invention-1s the provision of a hammer mill wherem the parts are novelly arranged to facilitate easy and accurate placement and removal of the screen.

Another object of the present invention is the contemplation of a hammer miil having a screen mounted therein to form the lower circumierential wall of a grinding chamber, said screen being held in the operative position by means carried by a closure adapted to cover an opening in the casing through which the screen may be inserted.

Other objects of this invention are simplicity and economy of manufacture, case and efliciency et operation, and adaptabihty to the grinding of materials to varying degrees of fineness.

Minor objects of the invention will appear during the course of the detailed specification, referring to the accompanving drawing, wherein the invention is fully shown.

Figure 1 is a side e]evation of a hammer mill embodying this invention.

Fig. 2 is an end elevation of the same.

Fig. 3 is an enlarged sectional view taken on line IIIIII cf Fig. 2.

Fig. 4 is a sectionai view taken on line IVIV of Fig. 3, with parts broken away.

Fig. 5 is a detailed view of the cam members parts shown in dotted fines.

Like reference characters designate similar parts, and the numeral 8 indicates a casing or housing made of a suitable material, such as sheet iron, which is adapted to properly enclose the grinding members. Casing 8 is provided with a. material inlet Il) adjacent its upper portion which communicates with a. suitabie hopper l2. Hammers l4 are mounted on shaft l6 by means of blocks l8, and bolts 2l). Shaft I6 is horizontally disposed, with its outer portions extending through the housing and rotatabiy mounted in bearings 22 which are carried by the side walls of the housing.

Any suitable driving means, such as pulley 24, is rigidly secured to one end of shaft 16, and is adapted to be driven through the intermediacy of belt 26 by a suitable motor. A grinding chamber 28 is formed within casing 8 by anvils 38, and screen 40, which are mounted in the fol- -lowing manner. Securely attached to the opposite side wal1s 34 are two ang1ed members 36,

to which the horizontafly disposed anvils 38 are secured at their opposite ends by means of bolts 38. In order to permit of the proper feeding of materials between the rotatably mounted hammers and theanvfls, the outer anvils are positioned tangentiafly to the direction of travel of the outer ends of said hammers.

The lower circumferential wall of the grinding chamber 28 is formed by a perforated plate or screen 40, the inner surface of which is concentric with the direction of travel of the hammers. and is spaced apart from the outer ends of said hammers a sufiicient distance to facilitate proper grinding or shredding of material therebetween. Screen 4!) is substantiaily semi-circular with its diametrically opposite edges substantially parallel with the axis thereof. One of these edges is adapted to fit behind a ledge 42 formed on the angled iron 44 and extending substantiaily across the grinding chamber 28.

Angled member 44 is secured at its ends to angle iron 36 by means of bolts 38, which aise secure one of the anvils in position. It should be noted that ledge 42 is set slightly outside of the face of anvil 30, thus precluding any possible chance of wear due to the action of the material being ground.

Screen 48 is supported adjacent its opposite ends by means of brackets 46 which are securely attached to side walis 34 by means of rivets 48. It is very apparent that these brackets or lugs 46 may be integral with walls 34. Brackets 46 are supplemented by short, arcuate brackets 50, which are securely attached to a closure 52 that is adapted to securely close opening 54 formed through one of the end walls of the casing adjacent said screen. This closure 52 is removably attached to the casing 8 by means of easily removable wing nuts 56. The edge of screen 40 adjacent closure 52 is provided with a slightly inclined flange 58 which is positioned above arcuate bracket 56 and beneath a pair of eccentric rollers or cams 68 which, when the closure is in the operative position, are adapted to be adjusted te force the screen downwardly so that its diametrically opposite edge will be forced tightly against angled iron 44.

It will be noted that cams 68 are substantially the frustrum of a cone, with the large end thereof extending inwardly, thus preventing the adjacent end of the screen 48 from moving inwardly. Cams 60 are provided with pins 62 which extend through openings 64 formed through closure 52 and are provided on their outer ends with ratchet wheels 66. These ratchet wheels are provided With squared hubs 68 which serve to receive a wrench, by means of which the cams 60 can be rotated.

Referring to Fig. 2 it will be noted that the teeth of the ratchet wheels 66 are disposed in opposite directions and that a spring pawl l0, fulcrumed on trunnion 72, is disposed with its outer ends respectively engaging the teeth of said ratchet wheels to preclude their rotation in one direction, thus making it possible to hold the cams in the operative position and against accidental movement. With two separate adjusting cams 60 it is apparent that should the fianged edge 58 of the screen be out of paraliel with the axis of the hammers, the screen can still be properly forced to the operative position by tuming the cams through diferent arcs. The screen as shown is a composite of several narrow, pertorated sheets rigidly attached together to present shoulders opposed to the direction of travel of the hammers, thus facilitating the proper grinding of the material. However, in this invention it is not essential that this type of screen be used since a plain, semi-cylindrical, perforated plate would answer the same purpose.

Hammer mills of this type are used for the production of ground materials of difierent fineness,' and it is necessary that the screen 40 be replaced by screens having difierent sized perforations. This. structure permits of easy and rapid changing of these screens in the following manner.

Hammers 14 are stopped in a substantally horizontal position, the operator removes thumb screws 56 and pulls the closure, together with arcuate bracket 50, outwardly, thus exposing the screen 40 which may be easily lifted from its support on brackets 46 and from underneath ledge 42. The other screen is then placed in position with its outer edge behind ledge 42 where it will be held in a suitable positon'so that the closure may again be positioned and secured by means of the thumb nuts.

Beiore removing closure 52, the operator reieases pawi 10 and turns the cam to the raised position where it remains until after the closure has again been positioned and the cams are again forced downwardly against fiange 58 to properly seat the screen.

It is apparent that screen Ml may be made without the inclined fiange 58 since the cam 60 might rest against the narrow edge of the screen to force the same to the operative position. Furmermore, fiange 58 might be formed by simpiy attaching to the screen, in any suitable manner, an angle iron. When the angled portion 15 omitted it would be necessary to place the screen against the closure 52 in order to preclude the escape of materials between the screen and closure.

It is desired t reserve the right to make any changes or alterations in this structure that might reasonably fall within the scope of the appended claims.

Having thus described the invention, what is claimed as new and desired to be secured by Letters Patent is:

1. A hammer mil] comprising a casing having an opening through one of its end walls; a closure for said opening. in said casing; a hammer rotatably mounted within said casing; an arcuate screen mounted in said casing in operative relation with said hammer; and means including arcuate brackets carried by said closure t0 engage beneath said screen to support it in the operative position.

2. A hammer mill comprising a casing having an opening formed through one of its end walls and having a grinding chamber'therein; hammers mounted for rotation in said chamber; a screen removably mounted within said casing to form the lower wall of said grinding chamber; a closure for said opening; brackets carried by said closure adapted to extend beneath said screen and adjustabie means carried by said closure to force said screen against said brackets to secure said screen in the operative position.

3. A hammer mili comprising a casing having an opening formed through one of its end walls and having a grinding chamber therein; hammers mounted for rotation in said chamber; a screen removably mounted within said casing to form the lower walls of said. grinding chamber; a closure for said opening; and a rotatably mounted cam carried by said casing within said chamber operable from the outside of the casing to clampingly engage the edge of said screen to secure it in the operative position.

4. A hammer miil comprising a casing having an opening formed in one of its end walls and a grinding chamber formed therein; hammers mounted for rotation within said grinding chamber; a removabie semi-cyiindrical screen positioned in said casing to form the lower circumferential wall of said grinding chamber with its opposite straight edges respectively adjacent the end walls of said casing; one of the straight edges of said screen being disposed between the top and bottom of the opening formed in the adjacent end wall of the casing; a closure for said opening; and arcuate brackets carried by said closure adapted to engage the arcuate surface of said screen when the parts are in.the operative position.

5. A hammer mil1 comprising a casing having an opening formed in one of its end walls and a grindng chamber formed therein; hammers mounted for rotation within said grinding chamber; a removable semi-cyiindrical screen positioned in said casing to form the lower circumferential wali of said grinding chamber with its opposite straight edges respectively adjacent the end walls of said casing; one of the straight edges of said screen being disposed between the top and bottom of the opening formed in the ad* jacent end wall of the casing; an angled member supported between the end walls opposite said opening adapted to serve as an abutment for the other edge of said screen; a closure adapted to close said opening; and means carried by said closure verticaiiy adjustable t0 engage the adjacent edge of said screen and force the opposite edge thereof tightly against said angled member when the closure is secured in the closed position, said screen-engaging means having operating means positioned outside of said chamber when the closure is in the operative position.

6. A hammer mi1l comprising a casing having a grinding chamber with revoluble hammers mounted therein; a screen removably mounted in said casing to form the lower circumferential wall of said chamber; brackets carried by the walls of said casing to support said screen; a closure adapted to close an opening formed through the wall of said casing; and members carried by said closure, shaped to conform t0 therebeneath at its opposite sldes to serve as supports therefor.

7. A hammer mill comprising a caslng having an opening formed through one of its end walls and having a grinding chamber therein; hammers mounted for rotation in sald chamber; a screen removably mounted within sald casing to form the lower wall of said grindlng chamber; a closure for said openlng; clamping means positioned withln sald chamber and supported for vertical adjustment on said closure; and operating means for said clamplng means extending through said closure and adapted to be operated from the outside of the chamber to move the clamping means toward or from the edge of said screen.

8. A hammer mil] comprlsing a casing having an openflng formed in one of its end walls and a grindlng chamber formed thereln; hammers mounted for rotation wlthin sald gflnding chamber; a closure for said opening, an abatting member carfled by the end wall opposite said openlng; a removable semicyfindrical screen positioned in said casing to form the lower circumferential wall of sald grinding chamber with its opposite straight edges respectlvely adjacent the end walls of said casing; one of the straight edges of said screen belng dlsposed between the top and bottom of the opening formed in the adjacent end waH of the casing and the other of said stralght edges belng positioned beneath said abutment; and means lncluding a cam carried by said closure and vertlcafly adjustable thereto to engage the adjacent stralght edge of the screen to force the opposite edge of the screen against sald abutment.

ELMER L. BARTELS. 

